CHSY1 encodes chondroitin sulfate synthase 1 (802 aa). Has both beta-1,3-glucuronic acid and beta-1,4-N-acetylgalactosamine transferase activity. Highest expression in Artery Aorta (53.7 TPM) and Lung (37.0 TPM).

Temtamy preaxial brachydactyly syndrome is associated with mutations in the CHSY1 gene on chromosome 15.

The CHSY1 protein participates in CHSY1 G19_L28del, Defective CHSY1 causes TPBS, and Defective CHSY1 does not transfer GlcA to chondroitin pathways.

CHSY1 is classified as a druggable target (Druggable Genome and Enzyme categories) with score 0.0.

Genetic testing for CHSY1 is available. Testing is considered confirmatory for diagnosis.

Phenotype severity distribution: 4 always present features, 2 common features.

Estimated prevalence: <1 in 1,000,000 (VERY_RARE).

No clinical trials have been registered for temtamy preaxial brachydactyly syndrome.

2 publications have been identified in PubMed for temtamy preaxial brachydactyly syndrome. Research spans Basic Science / Preclinical (50%) and Gene Therapy / Novel Therapeutics (50%).

Recent Publications

• Dutta P (2025). [PMID: 41298522](https://pubmed.ncbi.nlm.nih.gov/41298522/). *Nature communications*. [Basic Science / Preclinical]

• Izumikawa T (2025). [PMID: 41062067](https://pubmed.ncbi.nlm.nih.gov/41062067/). *The Journal of biological chemistry*. [Gene Therapy / Novel Therapeutics]